Effect of parity on colostral mineral concentrations of Holstein cows and value of colostrum as a mineral source for newborn calves.

Colostrum samples for 93 Holstein cows and blood samples of 49 newborn calves fed only colostrum for 1 wk postpartum were collected to clarify the effect of parity on colostral and plasma mineral concentration. The concentrations of colostral Ca, P, Mg, Na, Fe, Zn, Cu, and Mn were highest at parturition and decreased rapidly by 24 h postpartum. Three cows had an extremely low concentration of colostral Ca and P. Colostral Ca, P, and Mg at parturition decreased as lactation number increased and stabilized after the third lactation. Colostral Zn of primiparous cows at parturition tended to be higher than that of multiparous cows, but no effect on colostral Fe, Cu, and Mn was due to parity. Blood hematocrit and hemoglobin of newborn calves increased with greater lactation number of the dams, and the blood values were lowest at d 6 postpartum for calves born from primiparous cows. Plasma Ca of calves born from primiparous cows tended to be higher than those of calves from multiparous cows, and blood hemoglobin and plasma inorganic P concentrations of female calves were higher than those of males at d 1 postpartum. Blood hematocrit and hemoglobin and plasma Mg decreased with time postpartum, but plasma Zn and Cu increased. In general, lactation number was a major factor for alteration of colostral minerals of cows and mineral status of newborn calves.